THE BIG LAUGH COMEDY FESTIVALTonight until March 27Riverside Theatres, corner of Church and Market streets, ParramattaPrices varyMore information 8839 3399 or http://www.biglaughriverside.com.au.Kramer on Seinfeld is on March 19, $34.90/$31.90

'I was retired when the whole Cosmo Kramer thing started," says Kenny Kramer of his famous on-screen persona. "It was a blast."

After a few minutes chatting to Kramer, it's easy to understand why Larry David, his neighbour and co-creator of Seinfeld, couldn't resist writing a character based on him into the popular television series.

In his thick Bronx accent, the real Kramer explains how he made his fortune.

"I figured out a way to power those tiny red laser beams, LEDs [light-emitting diodes], with a hearing aid battery during the time when disco was really big and everyone was into it," says Kramer.

"So I wrapped plastic around them, made a whole heap of jewellery like earrings and chokers. They cost 30c to make and I sold them for $US15. We moved a ton of them."

Sounds like an episode of Seinfeld.

"Yeah, well I lived across the hall from Larry for 5 and a 1/2 years," says Kramer. "Who knew he was taking notes?"

He wasn't the only one. Kramer wasted no time cashing in on the success of the show.

As host of Kramer's Reality Tour, Kramer takes tourists to locations around New York City in a bus, dishing out great helpings of behind-the-scenes Seinfeld action to devotees of the show.

He's keen to share the dirt with Sydney audiences at the Big Laugh Comedy Festival next Friday during his one-man show, Kramer on Seinfeld.

"I have rare video footage, an interview with the Soup Nazi - you'll never see Seinfeld the same way again," he says. "It's an interesting, informative and funny show."

Nancy Cartwright, the voice of Bart Simpson, is also appearing at the festival in My Life as a 10-Year-Old Boy.

Australians performing at the festival include The Glass House presenter Dave Hughes, all-girl comedy cabaret act the Fabulous Singlettes, and Sean Taylor in Broadway's longest-running one-man show, Defending the Caveman.

So did David paint a fair and accurate picture of his friend in Seinfeld?

"I don't enter a room like Michael Richards, but neither [Cosmo nor I] have a good work ethic," says Kramer.

For a person with an aversion to work, Kramer has been busy touring with his show.

"I don't consider this work. Waking up to an alarm clock, dressing in a suit, going to an office and answering to a guy all day that you're smarter than and he's your boss - that's work. This is fun."